Electromagnetic marker devices for buried or hidden use

ABSTRACT

The present disclosure relates to electromagnetic marker devices for locating hidden or buried objects. One embodiment includes an antenna having a plurality of conductive windings enclosed in a housing made of a low dielectric constant material and an electronic circuit including a circuit board having circuit elements disposed thereon and electrically coupled to the conductive windings through a connector. The circuit elements receive an input signal having a first frequency from an above-ground transmitter, convert the input signal to a power supply to power up the electronic circuit, generate, in response to the input signal, an output signal having a second frequency different from the first frequency, and provide the output signal, via the antenna element, to an above-ground receiver.

FIELD

This disclosure relates generally to devices for marking objects orlocations. More specifically, but not exclusively, the disclosurerelates to electromagnetic marker devices for underground placement toaid in locating buried objects and provide extended signal reception andtransmission range.

BACKGROUND

The evolving complexity of hidden or buried infrastructure requiresprecise knowledge of location and identification of utilities such asutility lines (e.g., underground power lines, gas lines, phone lines,fiber optic cable conduits, cable television (CATV) cables, sprinklercontrol wiring, water pipes, sewer pipes, etc.) for purposes of avoidingcontact with other utilities as well as for enhancement, replacement,and/or repair. Such utility lines, collectively and individually hereinreferred to as “buried objects” or “buried utilities” may be buriedunder the ground and/or otherwise hidden from normal sight. Constructionand/or excavation operations may require locations and/or identificationof such utility lines be known so as to avoid costly and hazardousdamage or destruction of infrastructure.

Traditionally, different types of markers have been used to indicate thepresence of such buried objects. Most commonly known are above-groundaerosol paint or flag markers of different colors marked on a groundsurface to denote specific buried objects and provide visual indicationof location of such objects. Such paint or flag markers are usuallycolor-coded according to the type of buried object they denote. Otherkinds of markers include conventional underground RFID-type devices suchas the electrical marker balls made by 3M that are placed near objectsto be marked and are buried with the objects under the ground.

Conventional marker devices, such as marker balls, are passive devicesthat include a tuning circuit, which, upon receiving a signaltransmitting electromagnetic energy at a specific frequency, resonate ator near the same frequency. For instance, the received signal must be ator near enough to the resonant frequency to energize the marker device.A receiver such as a buried object locator antenna may be used to detectresonant signals from the marker balls to determine their presence andlocation.

Traditional marker balls or other conventional marker devices, thoughadvantageous over the above-ground paint and flag markers that are proneto chipping and fading, still suffer from various drawbacks. Forexample, these marker balls and other conventional marker devices oftenlack control over the received electromagnetic energy, which is oftenaffected by their form factor, component construction, manufacturingtolerances, underground environment (e.g., wet or otherwise conductivesoil) where the marker balls or other conventional marker devices areplaced, etc. This can negatively affect performance of such marker ballsor other conventional marker devices and result in a resonance signalhaving a gradually decayed amplitude often undetectable by acorresponding receiver or detectable, occasionally, with a limitedsignal range of 1 meter to 1.5 meters, thereby requiring close couplingwith the receiver. Further, having a resonance signal at the same ornearly the same frequency of the received signal can causebackscattering at the receiver, thereby resulting in substantialinterference which can make detection of the marker balls difficultand/or inaccurate.

The few marker balls and other conventional marker devices that do havesome control over the received electromagnetic energy do so in order tomodulate the signal (e.g., generally through phase or amplitude orfrequency signal keying) in order to communicate data rather than toimprove device performance. Consequently, such conventional markerdevices that modulate signals suffer from the same performance drawbacksas other conventional marker devices.

Accordingly, there is a need in the art to address the above-describedas well as other problems related to marker devices and associatedsystems for underground and similar applications.

SUMMARY

The disclosure relates to enhanced marker devices for placement below aground surface in proximity to a buried object for the purpose oflocating such object when required. The marker device may include anantenna element having a plurality of coil turns or windingselectrically coupled to an electronic circuit and arranged to provide,in conjunction with the electronic circuit, an extended signal receptionand transmission range of 2 or more meters facilitating improveddetection of such marker devices by an above-groundreceiver/transmitter.

In one aspect, the marker device may include a loop-shaped antennaelement having a plurality of coil turns arranged in a loop form withouter ends of the windings electrically coupled to the electroniccircuit.

In another aspect, the antenna element may include three individual coilturns connected in series with each coil turn electrically coupled tothe electronic circuit.

In another aspect, the antenna element may include three individual coilturns amongst which the first two coil turns may be connected in seriesand the third coil turn may be connected in parallel with each coil turnelectrically coupled to the electronic circuit.

In another aspect, the coil turns may be enclosed in a protectivehousing and may be arranged in a separated manner from each other witheach coil turn being electrically coupled to the electronic circuit.

In another aspect, the protective housing may be made of a lowdielectric material (e.g., material having a dielectric constant lessthan 3) and may additionally enclose air.

In another aspect, the electronic circuit may include a circuit boardand a plurality of circuit elements disposed thereon.

In another aspect, a connector may be provided to electrically couplethe plurality of individual coil turns to the circuit board. Theconnector may include connecting elements at each side of the circuitboard for coupling to outer ends of the coil turns. The circuit boardmay include electrical traces to which the connecting elements mayelectrically couple the coil turns.

In another aspect, the electronic circuit may be enclosed in aninsulating cover over-molded thereon to protect the circuit board andthe circuit elements disposed thereon from underground environment suchas soil and substance in the soil. The cover may also prevent ingress ofliquid or other contaminants in the electronic circuit.

In another aspect, the circuit elements may be configured to receive,via the antenna element, an input signal at a first frequency from anabove-ground transmitter (e.g., a buried object locator with anintegrated transmitter). The input signal induces current flow in thewindings sufficient to energize the circuit elements one or more ofwhich may generate an output signal responsive to the input signal. Theoutput signal may have a second frequency that is different from thefirst frequency (e.g., frequency of the input signal). Such an outputsignal may be transmitted to an above-ground receiver (e.g., the buriedobject locator) as a reply to the input signal to assist in determininglocation of the buried object.

In another aspect, a label may be disposed on or mechanically attachedto the protective housing or the insulating cover. Such a label mayinclude electronically-readable information pertaining to the markerdevice and may optionally include additional information pertaining toposition or characteristics of the marker device or associated buriedobject.

In another aspect, the label may be laser marked directly on theprotective housing, the insulating cover, and/or at other portions ofthe marker device.

In another aspect, one or more permanent magnets may be disposed in themarker device to generate magnetic field detectable by surveyinstruments or devices.

Various additional aspects, features, and functionality are furtherdescribed below in conjunction with the appended Drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure may be more fully appreciated in connection withthe following detailed description taken in conjunction with theaccompanying Drawings, wherein:

FIGS. 1A-1C illustrate embodiments of an enhanced marker device placedbelow a ground surface in proximity to a buried object.

FIGS. 1D-1E illustrate embodiments of an enhanced marker device buriedin proximity to a deeply buried object.

FIGS. 2A-2C illustrate embodiments of an enhanced marker deviceincluding a plurality of windings and associated elements.

FIGS. 3A-3C illustrate embodiments of an electronic circuit.

FIGS. 4A-4C illustrate embodiments of a connector for electricallycoupling the windings to the electronic circuit.

FIG. 5 illustrates a block diagram of the electronic circuit.

FIGS. 6A-6C illustrate embodiments of a label containingelectronically-readable information, disposed on the enhanced markerdevice.

FIGS. 7A-7B illustrate embodiments of a protective cover enclosing theelectronic circuit.

FIG. 8 illustrates a circuit diagram embodiment of the electroniccircuit with windings connected in series.

FIG. 9 illustrates a circuit diagram embodiment of the electroniccircuit with windings coupled in series and parallel combination.

FIGS. 10A-10M illustrate exemplary shapes of the enhanced marker deviceaccording to different embodiments of the present disclosure.

FIGS. 11A-11B illustrate exemplary dimensioned marker deviceembodiments.

FIGS. 12A-12G illustrate embodiments of the enhanced marker device andits use in conducting surveys.

DETAILED DESCRIPTION OF EMBODIMENTS Overview

This disclosure relates generally to enhanced marker devices that areplaced underground for the purpose of locating buried objects andprovide an extended signal reception and transmission range of two ormore meters.

According to various aspects of the present disclosure, an enhancedmarker device is disclosed that may be placed below a ground surface inproximity to a buried object for use in locating such object whenrequired. The enhanced marker device may receive/send signals (e.g.,radio frequency signals) from/to an above-ground transmitter/receiver,such as a buried object locator equipped with an excitation circuit(e.g., transmitter circuit) and an antenna element (e.g., receivercircuit), to assist in determining location of the buried object. Forexample, the marker device may include an antenna element coupled to anelectronic circuit to receive an input signal (e.g., a radio frequencysignal) having a first frequency from the above-ground transmitter andprovide the received signal to the electronic circuit, which generates,in response to the input signal, an output signal (e.g., another radiofrequency signal) having a second frequency that is substantiallydifferent from the first frequency. The generated output signal may beprovided as a reply to the above-ground receiver to assist indetermining location of the buried object associated with the markerdevice. The antenna element disclosed herein may include a plurality ofcoil turns electrically coupled, for example, in series or a combinationof series and parallel arrangement, to the electronic circuit toprovide, in conjunction with the electronic circuit, an extended signalreception and transmission range (e.g., 2 meters or more), therebyenabling signal communication between the transmitter/receiver and themarker device to be carried out effectively up to or even beyond 2meters of distance range.

Additional details and examples of the above-groundtransmitter/receivers such as buried object/utility locator that may beused in conjunction with the embodiments described subsequently hereinare disclosed in co-assigned patent applications including: U.S. Pat.No. 7,009,399, issued Mar. 7, 2006, entitled OMNIDIRECTIONAL SONDE ANDLINE LOCATOR; U.S. Pat. No. 7,136,765, issued Nov. 14, 2006, entitled ABURIED OBJECT LOCATING AND TRACING METHOD AND SYSTEM EMPLOYING PRINCIPALCOMPONENTS ANALYSIS FOR BLIND SIGNAL DETECTION; U.S. Pat. No. 7,221,136,issued May 22, 2007, entitled SONDES FOR LOCATING UNDERGROUND PIPES ANDCONDUITS; U.S. Pat. No. 7,276,910, issued Oct. 2, 2007, entitled ACOMPACT SELF-TUNED ELECTRICAL RESONATOR FOR BURIED OBJECT LOCATORAPPLICATIONS; U.S. Pat. No. 7,288,929, issued Oct. 30, 2007, entitledINDUCTIVE CLAMP FOR APPLYING SIGNAL TO BURIED UTILITIES; U.S. Pat. No.7,298,126, issued Nov. 20, 2007, entitled SONDES FOR LOCATINGUNDERGROUND PIPES AND CONDUITS; U.S. Pat. No. 7,332,901, issued Feb. 19,2008, entitled LOCATOR WITH APPARENT DEPTH INDICATION; U.S. Pat. No.7,336,078, issued Feb. 26, 2008, entitled MULTI-SENSOR MAPPINGOMNIDIRECTIONAL SONDE AND LINE LOCATORS; U.S. Pat. No. 7,443,154, issuedOct. 28, 2008, entitled MULTI-SENSOR MAPPING OMNIDIRECTIONAL SONDE ANDLINE LOCATOR; U.S. Pat. No. 7,498,797, issued Mar. 3, 2009, entitledLOCATOR WITH CURRENT-MEASURING CAPABILITY; U.S. Pat. No. 7,498,816,issued Mar. 3, 2009, entitled OMNIDIRECTIONAL SONDE AND LINE LOCATOR;U.S. Pat. No. 7,518,374, issued Apr. 14, 2009, entitled RECONFIGURABLEPORTABLE LOCATOR EMPLOYING MULTIPLE SENSOR ARRAYS HAVING FLEXIBLE NESTEDORTHOGONAL ANTENNAS; U.S. Pat. No. 7,557,559, issued Jul. 7, 2009,entitled COMPACT LINE ILLUMINATOR FOR LOCATING BURIED PIPES AND CABLES;U.S. Pat. No. 7,619,516, issued Nov. 17, 2009, entitled SINGLE ANDMULTI-TRACE OMNIDIRECTIONAL SONDE AND LINE LOCATORS AND TRANSMITTER USEDTHEREWITH; U.S. patent application Ser. No. 12/704,808, filed Feb. 12,2010, entitled PIPE INSPECTION SYSTEM WITH REPLACEABLE CABLE STORAGEDRUM; U.S. Pat. No. 7,733,077, issued Jun. 8, 2010, entitledMULTI-SENSOR MAPPING OMNIDIRECTIONAL SONDE AND LINE LOCATORS ANDTRANSMITTER USED THEREWITH; U.S. Pat. No. 7,741,848, issued Jun. 22,2010, entitled ADAPTIVE MULTICHANNEL LOCATOR SYSTEM FOR MULTIPLEPROXIMITY DETECTION; U.S. Pat. No. 7,755,360, issued Jul. 13, 2010,entitled PORTABLE LOCATOR SYSTEM WITH JAMMING REDUCTION; U.S. Pat. No.7,825,647, issued Nov. 2, 2010, entitled METHOD FOR LOCATING BURIEDPIPES AND CABLES; U.S. Pat. No. 7,830,149, issued Nov. 9, 2010, entitledAN UNDERGROUND UTILITY LOCATOR WITH A TRANSMITTER A PAIR OF UPWARDLYOPENING POCKETS AND HELICAL COIL TYPE ELECTRICAL CORDS; U.S. Pat. No.7,863,885, issued Jan. 4, 2011, entitled SONDES FOR LOCATING UNDERGROUNDPIPES AND CONDUITS; U.S. Pat. No. 7,948,236, issued May 24, 2011,entitled ADAPTIVE MULTICHANNEL LOCATOR SYSTEM FOR MULTIPLE PROXIMITYDETECTION; U.S. Pat. No. 7,969,419, issued Jun. 28, 2011, entitledPRE-AMPLIFIER AND MIXER CIRCUITRY FOR A LOCATOR ANTENNA; U.S. patentapplication Ser. No. 13/189,844, filed Jul. 25, 2011, entitled BURIEDOBJECT LOCATOR SYSTEMS AND METHODS; U.S. Pat. No. 7,990,151, issued Aug.2, 2011, entitled TRI-POD BURIED LOCATOR SYSTEM; U.S. Pat. No.8,013,610, issued Sep. 6, 2011, entitled HIGH Q SELF-TUNING LOCATINGTRANSMITTER; U.S. Pat. No. 8,035,390, issued Oct. 11, 2011, entitledOMNIDIRECTIONAL SONDE AND LINE LOCATOR; U.S. Pat. No. 8,106,660, issuedJan. 31, 2012, entitled SONDE ARRAY FOR USE WITH BURIED LINE LOCATOR;U.S. Pat. No. 8,203,343, issued Jun. 19, 2012, entitled RECONFIGURABLEPORTABLE LOCATOR EMPLOYING MULTIPLE SENSOR ARRAYS HAVING FLEXIBLE NESTEDORTHOGONAL ANTENNAS; U.S. patent application Ser. No. 13/584,799, filedAug. 13, 2012, entitled BURIED OBJECT LOCATOR SYSTEMS AND METHODS; U.S.Pat. No. 8,248,056, issued Aug. 21, 2012, entitled A BURIED OBJECTLOCATOR SYSTEM EMPLOYING AUTOMATED VIRTUAL DEPTH EVENT DETECTION ANDSIGNALING; U.S. Pat. No. 8,264,226, issued Sep. 11, 2012, entitledSYSTEMS AND METHODS FOR LOCATING BURIED PIPES AND CABLES WITH A MANPORTABLE LOCATOR AND A TRANSMITTER IN A MESH NETWORK; U.S. patentapplication Ser. No. 13/647,310, filed Oct. 8, 2012, entitled PIPEINSPECTION SYSTEM APPARATUS AND METHODS; U.S. patent application Ser.No. 13/769,202, Feb. 15, 2013, entitled SMART PAINT STICK DEVICES ANDMETHODS; U.S. patent application Ser. No. 13/787,711, Mar. 6, 2013,entitled DUAL SENSED LOCATING SYSTEMS AND METHODS; U.S. patentapplication Ser. No. 13/793,168, filed Mar. 11, 2013, entitled BURIEDOBJECT LOCATORS WITH CONDUCTIVE ANTENNA BOBBINS; U.S. Pat. No.8,395,661, issued Mar. 12, 2013, entitled PIPE INSPECTION SYSTEM WITHSELECTIVE IMAGE CAPTURE; U.S. patent application Ser. No. 13/826,112,Mar. 14, 2013, entitled SYSTEMS AND METHODS INVOLVING A SMART CABLESTORAGE DRUM AND NETWORK NODE FOR TRANSMISSION OF DATA; U.S. patentapplication Ser. No. 13/851,951, Mar. 27, 2013, entitled DUAL ANTENNASYSTEMS WITH VARIABLE POLARIZATION; U.S. patent application Ser. No.13/894,038, May 14, 2013, entitled OMNI-INDUCER TRANSMITTING DEVICES ANDMETHODS; U.S. patent application Ser. No. 13/925,636, Jun. 24, 2013,entitled MODULAR BATTERY PACK APPARATUS, SYSTEMS, AND METHODS INCLUDINGVIRAL DATA AND/OR CODE TRANSFER; U.S. Pat. No. 8,547,428, issued Oct. 1,2013, entitled PIPE MAPPING SYSTEM; U.S. Pat. No. 8,564,295, issued Oct.22, 2013, entitled METHOD FOR SIMULTANEOUSLY DETERMINING A PLURALITY OFDIFFERENT LOCATIONS OF THE BURIED OBJECTS AND SIMULTANEOUSLY INDICATINGTHE DIFFERENT LOCATIONS TO A USER; U.S. patent application Ser. No.14/077,022, filed Nov. 11, 2013, entitled WEARABLE MAGNETIC FIELDUTILITY LOCATOR SYSTEM WITH SOUND FIELD GENERATION; U.S. patentapplication Ser. No. 14/148,649, Jan. 6, 2014, entitled MAPPING LOCATINGSYSTEMS AND METHODS; U.S. Pat. No. 8,635,043, issued Jan. 21, 2014,entitled LOCATOR AND TRANSMITTER CALIBRATION SYSTEM; U.S. patentapplication Ser. No. 14/207,502, Mar. 12, 2014, entitled GRADIENTANTENNA COILS FOR USE IN LOCATING SYSTEMS; U.S. patent application Ser.No. 14/214,151, Mar. 14, 2014, entitled DUAL ANTENNA SYSTEMS WITHVARIABLE POLARIZATION; U.S. Pat. No. 9,703,002, issued Jul. 13, 2014,entitled UTILITY LOCATOR SYSTEMS AND METHODS; U.S. patent applicationSer. No. 14/446,145, Jul. 29, 2014, entitled UTILITY LOCATING SYSTEMSWITH MOBILE BASE STATION; U.S. Pat. No. 8,841,912, issued Sep. 23, 2014,entitled PRE-AMPLIFIER AND MIXER CIRCUITRY FOR A LOCATOR ANTENNA; U.S.patent application Ser. No. 14/709,301, filed May 11, 2015, entitledPIPE MAPPING SYSTEMS AND METHODS; U.S. Pat. No. 9,041,794, issued May26, 2015, entitled PIPE MAPPING SYSTEMS AND METHODS; U.S. Pat. No.9,057,754, issued Jun. 16, 2015, entitled ECONOMICAL MAGNETIC LOCATORAPPARATUS AND METHOD; U.S. patent application Ser. No. 14/797,760, Jul.13, 2015, entitled HAPTIC DIRECTIONAL FEEDBACK HANDLES FOR LOCATINGDEVICES; U.S. Pat. No. 9,081,109, issued Jul. 14, 2015, entitledGROUND-TRACKING DEVICES FOR USE WITH A MAPPING LOCATOR; U.S. patentapplication Ser. No. 14/800,490, Jul. 15, 2013, entitled UTILITY LOCATORDEVICES, SYSTEMS, AND METHODS WITH SATELLITE AND MAGNETIC FIELD SONDEANTENNA SYSTEMS; U.S. patent application Ser. No. 14/949,868, Nov. 23,2015, entitled BURIED OBJECT LOCATORS WITH DODECAHEDRAL ANTENNA NODES;U.S. Pat. No. 9,207,350, issued Dec. 8, 2015, entitled BURIED OBJECTLOCATOR APPARATUS WITH SAFETY LIGHTING ARRAY; U.S. patent applicationSer. No. 15/006,119, Jan. 26, 2016, entitled SELF-STANDING MULTI-LEGATTACHMENT DEVICES FOR USE WITH UTILITY LOCATORS; U.S. patentapplication Ser. No. 15/434,056, Feb. 16, 2016, entitled BURIED UTILITYMARKER DEVICES, SYSTEMS, AND METHODS; U.S. Pat. No. 9,341,740, issuedMay 17, 2016, entitled OPTICAL GROUND TRACKING APPARATUS, SYSTEMS, ANDMETHODS; U.S. patent application Ser. No. 15/187,785, Jun. 21, 2016,entitled BURIED UTILITY LOCATOR GROUND TRACKING APPARATUS, SYSTEMS, ANDMETHODS; U.S. Pat. No. 9,372,117, issued Jun. 21, 2016, entitled OPTICALGROUND TRACKING APPARATUS, SYSTEMS, AND METHODS; U.S. patent applicationSer. No. 15/225,623, Aug. 1, 2016, entitled SONDE-BASED GROUND-TRACKINGAPPARATUS AND METHODS; U.S. patent application Ser. No. 15/247,503, Aug.25, 2016, entitled LOCATING DEVICES, SYSTEMS, AND METHODS USINGFREQUENCY SUITES FOR UTILITY DETECTION; U.S. Pat. No. 9,927,546, issuedAug. 29, 2016, entitled PHASE SYNCHRONIZED BURIED OBJECT LOCATORAPPARATUS, SYSTEMS, AND METHODS; U.S. Pat. No. 9,435,907, issued Sep. 6,2016, entitled PHASE SYNCHRONIZED BURIED OBJECT LOCATOR APPARATUS,SYSTEMS, AND METHODS; U.S. Pat. No. 9,465,129, issued Oct. 11, 2016,entitled IMAGE-BASED MAPPING LOCATING SYSTEM; U.S. patent applicationSer. No. 15/339,766, Oct. 31, 2016, entitled GRADIENT ANTENNA COILS ANDARRAYS FOR USE IN LOCATING SYSTEMS; U.S. patent application Ser. No.15/345,421, Nov. 7, 2016, entitled OMNI-INDUCER TRANSMITTING DEVICES ANDMETHODS; U.S. Pat. No. 9,488,747, issued Nov. 8, 2016, entitled GRADIENTANTENNA COILS AND ARRAYS FOR USE IN LOCATING SYSTEM; U.S. Pat. No.9,494,706, issued Nov. 15, 2016, entitled OMNI-INDUCER TRANSMITTINGDEVICES AND METHODS; U.S. patent application Ser. No. 15/360,979, Nov.23, 2016, entitled UTILITY LOCATING SYSTEMS, DEVICES, AND METHODS USINGRADIO BROADCAST SIGNALS; U.S. patent application Ser. No. 15/376,576,filed Dec. 12, 2016, entitled MAGNETIC SENSING BURIED OBJECT LOCATORINCLUDING A CAMERA; U.S. Pat. No. 9,523,788, issued Dec. 20, 2016,entitled MAGNETIC SENSING BURIED OBJECT LOCATOR INCLUDING A CAMERA; U.S.patent application Ser. No. 15/396,068, filed Dec. 30, 2016, entitledUTILITY LOCATOR TRANSMITTER APPARATUS AND METHODS; U.S. patentapplication Ser. No. 15/457,149, Mar. 13, 2017, entitled USER INTERFACESFOR UTILITY LOCATORS; U.S. patent application Ser. No. 15/457,222, Mar.13, 2017, entitled SYSTEMS AND METHODS FOR LOCATING BURIED OR HIDDENOBJECTS USING SHEET CURRENT FLOW MODELS; U.S. patent application Ser.No. 15/457,897, Mar. 13, 2017, entitled UTILITY LOCATORS WITHRETRACTABLE SUPPORT STRUCTURES AND APPLICATIONS THEREOF; U.S. patentapplication Ser. No. 14/022,067, Mar. 21, 2017, entitled USER INTERFACESFOR UTILITY LOCATORS; U.S. Pat. No. 9,599,449, issued Mar. 21, 2017,entitled SYSTEMS AND METHODS FOR LOCATING BURIED OR HIDDEN OBJECTS USINGSHEET CURRENT FLOW MODELS; U.S. patent application Ser. No. 15/470,642,Mar. 27, 2017, entitled UTILITY LOCATING APPARATUS AND SYSTEMS USINGMULTIPLE ANTENNA COILS; U.S. patent application Ser. No. 15/470,713,Mar. 27, 2017, entitled UTILITY LOCATORS WITH PERSONAL COMMUNICATIONDEVICE USER INTERFACES; U.S. patent application Ser. No. 15/485,082,Apr. 11, 2017, entitled MAGNETIC UTILITY LOCATOR DEVICES AND METHODS;U.S. Pat. No. 9,625,602, issued Apr. 18, 2017, entitled SMART PERSONALCOMMUNICATION DEVICES AS USER INTERFACES; U.S. patent application Ser.No. 15/497,040, Apr. 25, 2017, entitled SYSTEMS AND METHODS FOR LOCATINGAND/OR MAPPING BURIED UTILITIES USING VEHICLE-MOUNTED LOCATING DEVICES;U.S. Pat. No. 9,632,202, issued Apr. 25, 2017, entitled ECONOMICALMAGNETIC LOCATOR APPARATUS AND METHOD; U.S. Pat. No. 9,634,878, issuedApril 25,2017, entitled SYSTEMS AND METHODS FOR DATA SYNCHRONIZINGQUADRATURE AMPLITUDE MODULATION (QAM); U.S. patent application Ser. No.15/590,964, May 9, 2017, entitled BORING INSPECTION SYSTEMS AND METHODS;U.S. Pat. No. 9,651,711, issued May 16, 2017, entitled HORIZONTAL BORINGINSPECTION DEVICE AND METHODS; U.S. patent application Ser. No.15/626,399, Jun. 19, 2017, entitled SYSTEMS AND METHODS FOR UNIQUELYIDENTIFYING BURIED UTILITIES IN A MULTI-UTILITY ENVIRONMENT; U.S. Pat.No. 9,696,447, issued Jul. 4, 2017, entitled BURIED OBJECT METHODS ANDAPPARATUS USING MULTIPLE ELECTROMAGNETIC SIGNALS; U.S. Pat. No.9,696,448, issued Jul. 4, 2017, entitled GROUND-TRACKING DEVICES FOR USEWITH A MAPPING LOCATOR; U.S. patent application Ser. No. 15/681,250,Aug. 18, 2017, entitled ELECTRONIC MARKER DEVICES AND SYSTEMS; U.S.patent application Ser. No. 15/681,409, filed Aug. 20, 2017, entitledWIRELESS BURIED PIPE AND CABLE LOCATING SYSTEMS; U.S. Pat. No.9,746,572, issued Aug. 29, 2017, entitled ELECTRONIC MARKER DEVICES ANDSYSTEMS; U.S. Pat. No. 9,746,573, issued Aug. 29, 2017, entitledWIRELESS BURIED PIPE AND CABLE LOCATING SYSTEMS; U.S. patent applicationSer. No. 15/728,250, Oct. 9, 2017, entitled OPTICAL GROUND TRACKINGAPPARATUS, SYSTEMS, AND METHODS FOR USE WITH BURIED UTILITY LOCATORS;U.S. Pat. No. 9,784,837, issued Oct. 10, 2017, entitled OPTICAL GROUNDTRACKING APPARATUS, SYSTEMS, AND METHODS; U.S. patent application Ser.No. 15/811,361, Nov. 13, 2017, entitled OPTICAL GROUND TRACKINGAPPARATUS, SYSTEMS, AND METHODS; U.S. Pat. No. 9,841,503, issued Dec.12, 2017, entitled OPTICAL GROUND TRACKING APPARATUS, SYSTEMS, ANDMETHODS; U.S. patent application Ser. No. 15/846,102, Dec. 18, 2017,entitled SYSTEMS AND METHODS FOR ELECTRONICALLY MARKING, LOCATING, ANDVIRTUALLY DISPLAYING BURIED UTILITIES; U.S. patent application Ser. No.15/866,360, Jan. 9, 2018, entitled TRACKED DISTANCE MEASURING DEVICE,SYSTEMS, AND METHODS; U.S. patent application Ser. No. 15/870,787, Jan.12, 2018, entitled MAGNETIC FIELD CANCELING AUDIO SPEAKERS FOR USE WITHBURIED UTILITY LOCATORS OR OTHER DEVICES; U.S. patent application Ser.No. 15/925,643, Mar. 19, 2018, entitled PHASE-SYNCHRONIZED BURIED OBJECTTRANSMITTER AND LOCATOR METHODS AND APPARATUS; U.S. patent applicationSer. No. 15/925,671, Mar. 19, 2018, entitled MULTI-FREQUENCY LOCATINGSYSTEMS AND METHODS; U.S. Pat. No. 9,924,139, issued Mar. 20, 2018,entitled PORTABLE PIPE INSPECTION SYSTEMS AND APPARATUS; U.S. patentapplication Ser. No. 15/936,250, Mar. 26, 2018, entitled GROUND TRACKINGAPPARATUS, SYSTEMS, AND METHODS; U.S. Pat. No. 9,927,545, issued Mar.27,2018, entitled MULTI-FREQUENCY LOCATING SYSTEM AND METHODS; U.S. Pat.No. 9,928,613, issued Mar. 27, 2018, entitled GROUND TRACKING APPARATUS,SYSTEMS, AND METHODS; U.S. patent application Ser. No. 15/954,486, filedApr. 16, 2018, entitled UTILITY LOCATOR APPARATUS, SYSTEMS, AND METHODS;U.S. Pat. No. 9,945,976, issued Apr. 17, 2018, entitled UTILITY LOCATORAPPARATUS, SYSTEMS, AND METHODS U.S. Provisional Patent Application62/688,259, filed Jun. 21, 2018, entitled ACTIVE MARKER DEVICES FORUNDERGROUND USE; U.S. Provisional Patent Application 62/726,500, filedSep. 4, 2018, entitled VIDEO PIPE INSPECTION SYSTEMS, DEVICES, ANDMETHODS INTEGRATED WITH NON-VIDEO DATA RECORDING AND COMMUNICATIONFUNCTIONALITY; U.S. patent application Ser. No. 16/178,494, filed Nov.1, 2018, entitled THREE-AXIS MEASUREMENT MODULES AND SENSING METHODS;U.S. Provisional Patent Application 62/777,045, filed Dec. 7, 2018,entitled MAP GENERATION BASED ON UTILITY LINE POSITION AND ORIENTATIONESTIMATES; and U.S. Provisional Patent Application 62/824,937, filedMar. 27, 2019, entitled LOW COST AND HIGH PERFORMANCE SIGNAL PROCESSINGIN A BURIED OBJECT LOCATOR SYSTEM. Further implementations may includeaspects and details of marker device embodiments as disclosed in U.S.Provisional Patent Application 62/864,441, filed Jun. 20, 2019, entitledELECTROMAGNETIC MARKER DEVICES WITH SEPARATE RECEIVE AND TRANSMITANTENNA ELEMENTS. The content of each of the above-described patents andpatent applications is incorporated by reference herein in its entirety.The above applications may be collectively denoted herein as the“co-assigned applications” or “incorporated applications.”

As used herein, the term “buried objects” include utilities below thesurface of the ground and utilities that are otherwise obscured,covered, or hidden from direct view or access, such as within walls,cavities, etc. In a typical application a buried object is a pipe,cable, conduit, wire, or other object made of a conductive material(e.g., metal, metal alloys, etc.) or a non-conductive material, (e.g.,plastic, concrete, ceramic, etc.) buried under the ground surface, at adepth of from a few centimeters to meters or more, that a user, such asa utility company employee, construction company employee, homeowner, orother wants to locate, map (e.g., by the position), and/or mark itslocation. Example utilities include water or other fluid pipelines,sewer lines, electrical power lines, electrical or optical signalinglines, gas lines, and the like.

The following exemplary embodiments are provided for the purpose ofillustrating examples of various aspects, details, and functions of thepresent disclosure; however, the described embodiments are not intendedto be in any way limiting. It will be apparent to one of ordinary skillin the art that various aspects may be implemented in other embodimentswithin the spirit and scope of the present disclosure. As used herein,the term, “exemplary” means “serving as an example, instance, orillustration.” Any aspect, detail, function, implementation, and/orembodiment described herein as “exemplary” is not necessarily to beconstrued as preferred or advantageous over other aspects and/orembodiments.

Various additional aspects, features, and functionality are furtherdescribed below in conjunction with the appended Drawings.

Example Embodiments

Details of example embodiments of an enhanced marker device placed underthe ground are shown in FIGS. 1A-1C. As shown in the FIG. 1A, anenhanced marker device 100 (hereinafter referred to as a “markerdevice”) may be placed under a ground surface 102 near a buried object104 for locating the buried object 104 when required. The ground surface102 may be of, for example, dirt or grass, a roadway, a sidewalk, abuilding floor, and the like under which the buried object(s) and themarker device(s) are placed.

The marker device 100 disclosed herein provides an extended signalreception and transmission range of 2 or more meters and may thereforereceive/send radio frequency signals from/to an above-groundtransmitter/receiver 120 located as far as 2 meters or beyond (e.g., 3meters) of range.

In an example illustrated in the FIG. 1A, the marker device 100 mayreceive an input signal 108 from a transmitter/receiver 120 located at adistance of about 2.5 meters from the marker device 100. The inputsignal 108 may a continuous or pulsed radio frequency signal having afirst frequency to energize the underground placed marker device 100.Energization may take place, for example, via extracting a portion ormore of the electrometric energy from the input signal 108 andconverting it into a power supply that may be used to power up one ormore of the circuit elements within the marker device 100.

When powered, the marker device 100 may generate an output signal 110,which may also be a continuous or pulsed radio frequency signal buthaving a second frequency different from the frequency of the receivedinput signal 108. The second frequency may be generated, for example, bydividing down the input signal frequency (i.e., first frequency). Theinput signal 108 may be divided down by a predefined value, such as 128or other divisor values, to generate the output signal 110. Forinstance, if the input signal 108 is at a first frequency, say,13,560,000 Hz, the output signal 110 may be generated to have afrequency of 105,937.5 Hz. Other frequencies and divide ratios mayalternately be used in various embodiments based on particular operatingenvironments, regulatory constraints, device constraints (e.g., powerreduction, etc.), signal loss, and the like. The generated output signal110 may be received by the transmitter/receiver 120 to assist indetermining location of the buried object 104.

The transmitter/receiver 120 disclosed herein may, in some embodiments,be integrated in a single device, for example, in a buried objectlocator disclosed in an embodiment illustrated in FIG. 1B or theintegrated buried object locator disclosed in the incorporatedapplications, in particular, U.S. Pat. No. 9,746,572, issued Aug. 29,2017, entitled ELECTRONIC MARKER DEVICES AND SYSTEMS, the contents ofwhich are incorporated by reference herein in their entirety.

Alternatively, the transmitter/receiver 120 may be in separate devices.The transmitter may be of conventional type capable of generatingrequired output frequency, or it may be a standalone marker excitationdevice as disclosed in the incorporated applications including U.S.patent application Ser. No. 15/434,056, filed Feb. 16, 2016, entitledBURIED UTILITY MARKER DEVICES, SYSTEMS, AND METHODS, the contents ofwhich are incorporated by reference herein in their entirety. Further,the receiver may be an antenna of conventional type capable of receivingwith required sensitivity a signal of the transmitted frequency, or itmay an antenna array arrangement included within a buried object locatordisclosed in the incorporated application including U.S. patentapplication Ser. No. 15/434,056, filed Feb. 16, 2016, entitled BURIEDUTILITY MARKER DEVICES, SYSTEMS, AND METHODS, the contents of which areincorporated by reference herein in their entirety.

According to a different embodiment, more than one marker devices may beplaced near the buried object and may assist in locating the buriedobject such as a utility pipeline. Such marker devices may be buried,for example, at regular or predefined intervals or near certain specificregions (e.g., joints, turns, etc.) of the utility pipeline based on itslayout and/or other factors.

FIG. 1C illustrates one such embodiment in which a plurality of markerdevices placed under the ground surface is illustrated. As shown, aplurality of marker devices 100-1, 100-2, 100-N, collectively referredto as marker devices 100, may be placed under the ground surface 102along an entire length of the buried object 104 at predefined or randomintervals, to assist in locating and tracing the buried object 104. Eachof these marker devices 100 may provide an extended signal reception andtransmission range of, say, 2-5 meters that enables one or more of thesemarker devices 100 to be detectable by the transmitter/receiver 120. Inone embodiment, a plurality of marker devices 100 within this range ofup to 2-5 meters from the transmitter/receiver 120 may be energizedsubstantially simultaneously.

In certain regions, objects may be buried more deeply than the otherregions. For example, in certain cold climate regions, depending uponthe frost line some objects such as gas pipelines may need to be buriedmore deeply (e.g., 5-6 feet below the ground surface) than other regionsor other objects. In such cases, it may be desirable to place the markerdevice in proximity to such deeply buried objects.

Illustrated in the FIGS. 1D and 1E are embodiments of enhanced markerdevice(s) buried in proximity to a deeply buried object. As shown, themarker device 100 (shown in FIG. 1D) or the plurality of marker devices100-1, 100-2, 100-N, collectively referred to as marker devices 100(shown in FIG. 1E) may be buried in proximity to a deeply buried object104. As noted above, such marker device(s) 100 has an extended signalreception and transmission range (e.g., 2-5 meters), such an extendedrange may render the deeply buried marker device(s) 100 detectable bythe above-ground transmitter/receiver 120, such as the buried objectlocator with an integrated transmitter.

Further details of the marker device and associated components aredescribed with reference to the FIGS. 2A-2C.

As shown in the FIG. 2A, the marker device 100 may include a pluralityof coil turns (interchangeably referred to as ‘antenna coil turns’ or‘windings’), for example, three coil turns 202 a, 202 b, 202 c(collectively referred to as coil turns 202) made of a conductivematerial such as copper, copper alloy, or other high conductivematerials such as silver, gold, etc. In an embodiment, the coil turns202 may be made of a copper-clad steel providing mechanical strength andmay aid in maintaining the desired shape of coil turns 202 and overallmarker device 100 while minimizing impedance at high operatingfrequencies due to the well-known skin effect of the current flow.

The coil turns 202 may be enclosed in protective housing 204 (shown inFIGS. 2B and 2C) made of a material having a low dielectric constant(e.g., polymers such as those having low dielectric constant,polypropylene (2.2-2.36), polyethylene (2.25), polystyrene (2.4-2.7),polytetrafluoroethylene (2.25), or other materials having a similarlylow dielectric constant number) and it may additionally enclose air, toreduce capacitive coupling to the ground or underground environment inwhich the marker device 100 is buried. The housing 204 may protect thewindings 202 from corrosive and otherwise damaging elements in theunderground environment. Further, the housing 204 may have a predefinedthickness (e.g., a thickness of approximately twice the diameter of thewindings) to provide a physical distance between the coil turns 202 andthe soil or the underground environment or a thickness determined basedon various factors/parameters, including but not limited to, frequenciesbeing utilized. The housing 204 and the physical distance created fromthe windings 202 may reduce capacitive coupling of both reception andtransmission signals with the soil or other conductive elements in thesoil, thereby reduce detuning of the marker device 100. The housing mayfurther prevent ingress of ions, further reducing detuning of the markerdevice 100.

In an embodiment, the coil turns 202 may be individual coil turnsarranged in a separated manner from each other in the housing 204, asshown in the FIG. 2A. Further, the coil turns 202 may be electricallycoupled to an electronic circuit 206 (FIG. 2B) responsible for signalhandling (e.g., processing of received input signals and generation ofoutput signal).

Exemplary embodiments of such an electronic circuit are illustrated bythe FIGS. 3A-3C showing a front, isometric and rear view of an exemplaryelectronic circuit 206, respectively. As shown, the electronic circuit206 may include a circuit board 302 (e.g., a printed circuit board) anda plurality of circuit elements 304 disposed thereon. The coil turns 202may be electrically coupled to the circuit elements on the circuit board302 via a connector.

Referring to FIGS. 4A-4C, exemplary connector embodiments areillustrated. As shown, the connector 400 may include a connecting base402 and a plurality of connecting elements, for example, the connectingelements 404 a, 404 b, and 404 c for coupling first ends of the coilturns 202 a, 202 b and 202 c to one side of the circuit board 302, andthe connecting elements 404 d, 404 e and 404 f for coupling the secondends of the coil turns 202 d, 202 e and 202 f to the other side of thecircuit board 302. The coil turns 202 may be sorted or fixed to thecorresponding connecting elements 404, which are then mounted to thecircuit board 302 via screws or other fixation elements, as shown in theFIGS. 4B and 4C. An electrical connection between the windings 202 andthe circuit board 302/associated circuit elements 304 may be establishedvia electrical circuit traces 408 (FIG. 4C) on the rear of the circuitboard 302. Such an arrangement advantageously maintains the electricalconnection between the coil turns 202 and the electronic circuit andpossesses nearly no risk of losing connection due to breakage and/orloosening of the coil turns 202.

Turning to FIG. 5, a block diagram of the exemplary electronic circuit206 is illustrated. As noted above, the electronic circuit 206 mayinclude a circuit board 302 (e.g., a printed circuit board) and aplurality of circuit elements 304 disposed thereon (FIGS. 3A-3B). Suchcircuit elements 304 may include, for example, an input circuit 502, apower circuit 504, an output circuit 506, a processing circuit/element508, a non-transitory memory 510, and/or other circuit elements to carryout programmed instructions. One or more of these circuits may includetuning elements (e.g., small value capacitors) controlled and/oradjusted automatically based on program instructions stored in thenon-transitory memory 510, for auto-tuning of the marker device 100. Thecircuit elements 304 may further include a control circuit (not shown)programmed to selectively enable or disable other circuit elementsdepending upon their usage, function, and/or operating status, etc., tosave power and optimize operation of the marker device 100.

Amongst the circuit elements, the input circuit 502 operates inconjunction with the antenna coil turns 202 to receive an input signalfrom the above-ground transmitter. From the input signal, the powercircuit extracts the electromagnetic energy and converts it into a DCpower to generate a power supply signal which may be used to power upother circuit elements. The processing element 508 may process thereceived input signal to generate an output signal which is responsiveto the input signal and has a frequency different from the frequency ofthe input signal. The generated output signal may be provided to theantenna coil turns 202 via the output circuit 506 and transmitted by thecoil turns 202, whereby the transmitted signal may be received by theabove-ground receiver. The output signal may assist in determining thelocation of the buried object.

In an embodiment, information pertaining to the marker device and/orburied object may be embedded into the output signal. For example, theprocessing element 508 may obtain information pertaining to the markerdevice, such as serial number of the device, device ID, and/or otherdata stored in the non-transitory memory 510 and/or from a labelcontaining electronically-readable information pertaining to the markerdevice, attached to or disposed on the marker device, and embed suchinformation into the output signal. Alternatively, such information maybe communicated to the above-ground transmitter/receiver via a separatesignal.

FIGS. 6A-6C illustrate embodiments of an exemplary label 602 attached toor disposed on the marker device 100. As shown, the label 602 mayinclude electronically-readable information (e.g., device ID, serialnumber, dimensions, or other data) pertaining to the marker device 100.The electronically-readable information may be in the form aradio-frequency identification (RFID) tag, a quick response (QR) code, abarcode, a microchip, or the like. Additionally, the label 602 mayinclude human-readable information (not shown) printed thereon. Suchhuman-readable information may include a portion of or all of theelectronically-readable information and/or additional information usefulfor users. For instance, the label 602 may include dimensions of themarker device 100 (e.g., 100 mm), device number (e.g., ‘XYZ 0002’)associated with the marker device 100, serial code (e.g., ‘00001000’),and/or other information pertaining to the marker device 100. The serialcode may be, but is not restricted to, an 8 bit code. In an example, thelabel 602 may be wrapped around a connector, such as a snap lockconnector having connector elements 604 a and 604 b locked together whenmated, as shown in the FIG. 6C. According to another embodiment (notillustrated), the label may be laser marked on the protective housing,the insulating cover, and/or at other portions of the marker device. Forexample, the label may be laser marked on the surface of the housingmade of a low dielectric constant polymer material. A laser markingadditive (e.g., OnCap™ additive from PolyOne Corporation(www.polyone.com) or other laser marking additives known in the art, ortheir combinations) may be added to or dispersed in the polymer materialof the housing to laser mark the label directly on the surface of thehousing.

Returning to FIG. 5, the electronic circuit 206 may additionally includea control circuit (not shown) to selectively enable or disable othercircuit elements depending upon usage, function, and/or operatingstatus, etc. of such elements, to save power. Further, the electroniccircuit 206 may include timing circuits (not shown) which may be used inconjunction with the control circuit for timer based control of thepower circuits or other circuit elements. One or more of the circuitelements 304 described above and/or additional circuit elements may beprovided to communicate information (e.g., serial number or other markerdevice information) from the underground placed marker device 100through signal modulation (e.g., amplitude signal keying (ASK), phasesignal keying (PSK), frequency signal keying (FSK), or the like).

In order to protect the electronic circuit 206 from the undergroundenvironment, an insulating cover may be provided to enclose the circuitboard and the circuit elements. The cover may be over-molded on theelectronic circuit. Alternatively, the cover may be disposed around theelectronic circuit in another sealing manner to protect the circuitboard and circuit elements from the underground contaminants.

According to the embodiment illustrated in the FIGS. 7A and 7B, thecover 702 may be over-molded on the electronic circuit and portions ofthe protective housing 204, to prevent ingress of moisture, liquid orother contaminants. The cover 702 may be made of a material having a lowdielectric constant (e.g., polymers having dielectric constant less than3, polypropylene (2.2-2.36), polyethylene (2.25), polystyrene (2.4-2.7),polytetrafluoroethylene (2.25), or other materials having a similarlylow dielectric constant number) and it may optionally include air. Thecover 702 may have a predefined thickness, for example, a thickness ofapproximately twice the diameter of the coil(s) or a thicknessdetermined based on various factors/parameters, including but notlimited to, frequencies being utilized, to reduce or prevent detuning ofthe marker device 100.

Turning to the FIG. 8, a circuit diagram of the electronic circuit 206and its connection with antenna windings 202 is illustrated. As shown,the antenna includes three coil turns 202 a, 202 b and 202 c all ofwhich may be connected in series to the electronic circuit 206. Inanother embodiment shown in the FIG. 9, two of the coil turns (e.g., 202a and 202 b) may be connected in series and the third one (202 c) inparallel to the electronic circuit 206.

The embodiments of the marker device 100 disclosed herein and shown inthe appended drawings relate mostly to a loop-shaped or ring-shapedmarker device 100 having antenna coil turns 202 arranged to form a loopwith its outer free ends electrically coupled to each side of thecircuit board 302. Different views of such a loop or ring shaped markerdevice 100 is further illustrated in the FIGS. 10A-10D. This shape andarrangement, however, is not intended to be construed in a limitingsense. The marker device 100, according to other embodiments of thepresent disclosure, may be designed in several other shapes, includingbut not limited or restricted to, a square shape as shown in the FIG.10E, a rectangular shape as shown in the FIG. 10F, an oblong shape asshown in the FIG. 10G, a pin or capsule like shape/configuration asshown in the FIGS. 10H-10M, and several other shapes (not shown for thesake of brevity) incorporating one or more of the features, elementsand/or functionalities described in the foregoing and forthcomingembodiments without deviating from the scope of the present disclosure.

Further, dimensions of the marker device 100 may vary depending upon anunderground environment and/or kind of object to be marked, and/orvarious other factors, and differently dimensioned marker devices mayprovide different signal reception and transmission range. By way ofexample and not as a limitation, illustrated in the FIG. 11A is themarker device 100 in loop-shape having three antenna coil turns and adiameter of about 100 mm, may provide a signal reception andtransmission range of about 2.5 meters, while in FIG. 11B, the markerdevice with a diameter of about 250 mm may provide the signal receptionand transmission range of about 3 meters.

Turning to the FIGS. 12A-12G, other embodiments of the marker device 100and its use in a geographical survey is illustrated. According to theseembodiments, the marker device 100 may include one or more permanentmagnets attached to or disposed on the marker device 100 to facilitatedetection by a survey instrument. For example, in a loop-shaped markerdevice embodiment shown in the FIGS. 12A-12B, the permanent magnet 1210may be disposed in the snap lock connector having connector elements 604a and 604 b locked together about the insulated housing 204 when mated.Alternatively, the permanent magnet 1210 and/or additional permanentmagnet(s) may be disposed at other portions of the marker device 100.

Further, in a capsule or pin shaped configuration of the marker device100 shown in the FIGS. 12C-12G, a pair of permanent magnets 1210 may bedisposed at two opposing ends of the marker device 100 with the polarityof the magnets being aligned to each other. Alternatively, one or morepermanent magnets may be disposed at other portions of the marker device100. The permanent magnets may comprise ferrite magnet material. Such acapsule or pin shaped configuration of the marker device 100 may includean insulated housing 204 made of, for example, a fiberglass or otherdielectric materials encapsulating a ferrite core 1220 having aplurality of coil turns 202 helically wrapped about the ferrite core1220. Further encapsulated in the insulated housing 204 is an electroniccircuit 206 which is electrically coupled to the coil turns 202. In oneembodiment, any vacant space(s) inside the insulating housing may befilled with an epoxy resin, a silicon rubber, and/or other fillermaterials.

Ends of the insulating housing 204 may be covered by protective endpieces 206, which may be over-molded in the insulating housing 204 attwo opposing ends to prevent ingress of liquid or other contaminantsinside the housing 204 and protect the electronic circuit 206, coilturns 202 and other elements inside the insulating housing 204 from suchcontaminants and other contaminants in the underground environment.Shown in the FIG. 12E is a cross-sectional view of such capsule or pinshaped marker device 100. Further, shown in the FIG. 12F is anotherembodiment of the capsule or pin shaped marker device 100 with hooks1230 disposed on the end pieces 206 for purposes including tying up awire, string or cable to suspend, push, or pull the marker device 100for placement/removal of the marker device 100 to/from the underground.

The magnets disposed in the marker device 100 generate magnetic fields,such as DC magnetic field 1204 in addition to the AC magnetic field 1206generated by the marker device 100. These magnetic fields may bedetectable by the survey instrument 1202 and/or one or more other surveyinstruments. The survey instrument 1202 may include any data collectioninstrument or a tool implementing a scientific protocol or executing aset of computer instructions, for obtaining data from respondent(s). Thesurvey instrument 1202 may be, for example, a survey drone or othersimilar instruments known in the art, or it may be a buried objectlocator or another data collection instrument disclosed in theincorporated applications. In addition to the permanent magnets or inplace of permanent magnets, other respondents or transponders known inthe art may be utilized for enabling detection by the survey instrument1202.

In one or more exemplary embodiments, the electronic features andfunctions described herein and associated with the marker device may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on or encoded asone or more instructions or code on a computer-readable medium.Computer-readable medium includes computer storage media. Storage mediamay be any available media that can be accessed by a computer. By way ofexample, and not limitation, such computer-readable media can compriseRAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic diskstorage or other magnetic storage devices, solid state drives (SSD), USBflash drives or other similar portable devices, or any other medium thatcan be used to carry or store desired program code in the form ofinstructions or data structures and that can be accessed by a computer.Disk and disc, as used herein, include compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and Blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of computer-readable medium. As used herein,computer program products comprising computer-readable media include allforms of computer -readable media except to the extent that such mediais deemed to be non-statutory, transitory propagating signals.

Those of skill in the art would understand that information and signals,such input/output signals or data, and/or other signals/other data maybe represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Skilled artisans may implement the described functionality in varyingways for each particular application, but such implementation decisionsshould not be interpreted as causing a departure from the scope of thepresent disclosure.

The various illustrative functions and circuits described in connectionwith the embodiments disclosed herein may be implemented or performed ina processing element with a general purpose processor, a digital signalprocessor (DSP), an application specific integrated circuit (ASIC), afield programmable gate array (FPGA) or other programmable logic device,discrete gate or transistor logic, discrete hardware components, memorydevices, and/or any combination thereof designed to perform thefunctions described herein. A general purpose processor may be amicroprocessor, but in the alternative, the processor may be anyconventional processor, controller, microcontroller, or state machine. Aprocessor may also be implemented as a combination of computing devices,e.g., a combination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration.

The features described in connection with the embodiments disclosedherein may be embodied directly in hardware, in a software moduleexecuted by a processor, or in a combination of the two. A softwaremodule may reside in RAM memory, flash memory, ROM memory, EPROM memory,EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or anyother form of storage medium known or developed in the art. An exemplarystorage medium is coupled to the processor such that the processor canread information from, and write information to, the storage medium. Inthe alternative, the storage medium may be integral to the processor.The processor and the storage medium may reside in an ASIC. The ASIC mayreside in the marker device disclosed herein.

The scope of the presently claimed invention is not intended to belimited to the aspects shown and described previously herein, but shouldbe accorded the full scope consistent with the description and drawingsas reflected in the language of the claims, wherein reference to anelement in the singular is not intended to mean “one and only one”unless specifically so stated, but rather “one or more.” Unlessspecifically stated otherwise, the term “some” refers to one or more. Aphrase referring to “at least one of” a list of items refers to anycombination of those items, including single members. As an example, “atleast one of: a, b, or c” is intended to cover: a; b; c; a and b; a andc; b and c; and a, b and c.

The previous description of the disclosed aspects is provided to enableany person skilled in the art to make or use embodiments of the presentinvention. Various modifications to these aspects will be readilyapparent to those skilled in the art, and the generic principles definedherein may be applied to other aspects without departing from the spiritor scope of the invention. Thus, the presently claimed invention is notintended to be limited to the aspects shown herein but is to be accordedthe widest scope consistent with the appended claims and theirequivalents.

We claim:
 1. A marker device for locating a buried object, comprising: ahousing made of a low dielectric constant (low K) material having adielectric constant (K) less than 3; an antenna element comprising aplurality of conductive windings enclosed in the housing; and anelectronic circuit comprising a circuit board electrically coupled tothe conductive windings through a connector, the connector includingconnecting elements at each side of the circuit board for coupling toouter ends of the conductive windings, wherein the circuit boardincludes electrical traces and the connecting elements electricallycouple the conductive windings to the electrical traces in the circuitboard, the circuit board comprising a plurality of circuit elementsdisposed thereon, the circuit elements including: an input circuit toreceive, via the antenna element, an input signal from an above-groundtransmitter, wherein the input signal has a first frequency; a powercircuit to convert the input signal to a power supply for powering theelectronic circuit; a processing element to generate an output signalresponsive to the input signal; and an output circuit to provide theoutput signal, via the antenna element, to an above-ground receiver toassist in determining a location of the buried object, wherein theoutput signal has a second frequency different from the first frequency;wherein the conductive windings in conjunction with the electroniccircuit are arranged in a configuration to provide a signal receptionand transmission range of two meters or more.
 2. The marker device ofclaim 1, wherein the conductive windings are arranged in a separatedmanner from each other in the housing.
 3. The marker device of claim 1,wherein the conductive windings are connected in series and electricallycoupled to the electronic circuit.
 4. The marker device of claim 1,wherein the conductive windings include a first winding, a secondwinding, and a third winding, the first and second windings areconnected in series and the third winding is connected in parallel, eachof the first, second and third windings being electrically coupled tothe electronic circuit.
 5. The marker device of claim 1, wherein theantenna element comprises three conductive windings.
 6. The markerdevice of claim 1, further comprising a protective cover over-molded onthe electronic circuit and portions of the housing.
 7. The marker deviceof claim 1, further comprising a label disposed on or mechanicallyattached to the housing, the label including electronically-readableinformation pertaining to the marker device.
 8. The marker device ofclaim 7, wherein the electronically-readable information includes aserial code associated with the marker device to uniquely identify themarker device.
 9. The marker device of claim 1, wherein the above-groundreceiver includes one or more antennas and the above-ground transmitterincludes an excitation circuit, both integrated in a buried objectlocator.
 10. The marker device of claim 1, wherein the electroniccircuit includes one or more tuning elements to tune the output signal,wherein the tuned output signal has an amplitude greater than that ofthe generated output signal.
 11. The marker device of claim 1, whereinthe circuit elements of the electronic circuit are selectively enabledor disabled to reduce power consumption.
 12. The marker device of claim1, further comprising one or more permanent magnets disposed in themarker device to generate magnetic fields detectable by a surveyinstrument.
 13. The marker device of claim 1, wherein the marker deviceprovides an extended signal reception and transmission range of 2-5meters.
 14. The marker device of claim 1, wherein the marker device isconfigured in a loop or ring shape.
 15. The marker device of claim 1,wherein the marker device is configured in a capsule or pin shape. 16.The marker device of claim 15, wherein the capsule or pin shape markerdevice comprises a permanent magnet disposed at each of the two endsthereof to generate magnetic fields detectable by a survey instrument.17. The marker device of claim 1, wherein the marker device isconfigured in a square shape, a rectangular shape, or an oblong shape.18. A marker device for locating a buried object, comprising: aloop-shaped housing made of a dielectric material; a loop-shaped antennaelement comprising three conductive windings enclosed in the housing ina separated manner from each other; and an electronic circuitelectrically coupled to the conductive windings through a connector, theconnector including conductive connecting elements to electricallycouple outer ends of the corresponding conductive windings to theelectronic circuit, the electronic circuit comprising: an input circuitto receive an input signal at a first frequency; a power circuit toconvert the input signal to a power supply for powering the electroniccircuit; a processing element to generate an output signal responsive tothe excitation signal; and an output circuit to provide the outputsignal at a second frequency different from the first frequency; whereinthe conductive windings in conjunction with the electronic circuit arearranged in a configuration to provide a signal reception andtransmission range of two meters or more.
 19. The marker device of claim18, wherein the electronic circuit includes a printed circuit boardhaving electrical traces thereon.
 20. The marker device of claim 18,wherein outer ends of the conductive windings are fixed to theconductive connecting elements on each side of the printed circuitboard, wherein the connecting elements are mechanically coupled to theelectrical traces in the printed circuit board.
 21. The marker device ofclaim 18, wherein the three conductive windings are connected in seriesand electrically coupled to the electronic circuit.
 22. The markerdevice of claim 18, wherein the three conductive windings include afirst conductive winding, a second conductive winding and a thirdconductive winding, wherein the first and second conductive windings areconnected in series and the third conductive winding is connected inparallel, each of the three windings are electrically coupled to theelectronic circuit.
 23. The marker device of claim 18, wherein themarker device provides a signal reception and transmission range ofbetween two and five meters.
 24. The marker device of claim 18, furthercomprising a protective cover over-molded on the electronic circuit andportions of the loop-shaped housing.
 25. The marker device of claim 24,further comprising one or more permanent magnets disposed in theprotective cover, to generate magnetic fields detectable by a surveyinstrument.
 26. The marker device of claim 24, further comprising alabel disposed on or mechanically attached to the loop-shaped housing orthe protective cover, the label including electronically-readableinformation pertaining to the marker device.
 27. The marker device ofclaim 26, wherein the electronically-readable information includes aserial code associated with the marker device, to uniquely identify themarker device.
 28. The marker device of claim 18, further comprising alabel laser marked on a surface of the loop-shaped housing or theprotective cover, the label including information pertaining to themarker device.
 29. The marker device of claim 28, wherein theinformation is electronically-readable.
 30. The marker device of claim28, wherein a laser marking additive is added to the dielectric materialof the loop-shaped housing to laser mark the label thereon, thedielectric material comprises a polymer.
 31. The marker device of claim1, further comprising a label including electronically-readableinformation pertaining to the marker device, the label being lasermarked on a surface of the housing.
 32. The marker device of claim 1,wherein the low dielectric constant material of the housing comprises alaser marking additive.
 33. The marker device of claim 1, wherein thelow dielectric constant material of the housing comprises a polymer. 34.The marker device of claim 1, wherein the low dielectric constantmaterial of the housing comprises a polymer and a laser marking additivedispersed in the polymer.